ZooMSS Dynamic Model Comparison

Overview

This document compares ZooMSS dynamic model outputs across different chlorophyll scenarios to examine how environmental forcing affects zooplankton community dynamics.

Model Scenarios

• Low Chlorophyll (0.01 mg m⁻³): Oligotrophic conditions representing nutrient-poor environments
• Medium Chlorophyll (0.1 mg m⁻³): Mesotrophic conditions with moderate productivity
• High Chlorophyll (4.0 mg m⁻³): Eutrophic conditions with high productivity
• Linear Chlorophyll: Gradually increasing chlorophyll over time
• Seasonal Chlorophyll: Seasonal variation patterns in chlorophyll

library(tidyverse)
library(patchwork)

source("zPlot.R")

Load Model Results

# Load constant chlorophyll scenarios
load("20250806_chl0_01_0001.RData")  # 0.01 mg m-3 chl (oligotrophic)
out1 <- out

load("20250806_chl0_1_0001.RData")   # 0.1 mg m-3 chl (mesotrophic)
out2 <- out

load("20250806_chl4_0_0001.RData")   # 4.0 mg m-3 chl (eutrophic)
out3 <- out

# Load dynamic chlorophyll scenarios
load("20250806_linear_0001.RData")   # Linear increasing chl
out4 <- out

load("20250806_Seasonal_0001.RData") # Seasonal chl patterns
out5 <- out

Abundance Time Series Comparison

Compare abundance patterns across all chlorophyll scenarios to understand how different productivity levels affect zooplankton population dynamics.

(zPlot_AbundTimeSeries(out1) + ggtitle("Low Chlorophyll (0.01 mg m⁻³)")) /
  (zPlot_AbundTimeSeries(out2) + ggtitle("Medium Chlorophyll (0.1 mg m⁻³)")) /
  (zPlot_AbundTimeSeries(out3) + ggtitle("High Chlorophyll (4.0 mg m⁻³)")) /
  (zPlot_AbundTimeSeries(out4) + ggtitle("Linear Increasing Chlorophyll")) /
  (zPlot_AbundTimeSeries(out5) + ggtitle("Seasonal Chlorophyll Patterns"))

Biomass Time Series - All Species

Proportional biomass plots showing relative contribution of each species to total community biomass across scenarios.

((zPlot_BiomassTimeSeries(out1, proportional = TRUE) + ggtitle("Low Chlorophyll (0.01 mg m⁻³)")) /
    (zPlot_BiomassTimeSeries(out2, proportional = TRUE) + ggtitle("Medium Chlorophyll (0.1 mg m⁻³)")) /
    (zPlot_BiomassTimeSeries(out3, proportional = TRUE) + ggtitle("High Chlorophyll (4.0 mg m⁻³)")) /
    (zPlot_BiomassTimeSeries(out4, proportional = TRUE) + ggtitle("Linear Increasing Chlorophyll")) /
    (zPlot_BiomassTimeSeries(out5, proportional = TRUE) + ggtitle("Seasonal Chlorophyll Patterns"))) +
  plot_layout(guides = 'collect')

Biomass Time Series - Key Species

Focus on major zooplankton functional groups to highlight ecological patterns and trophic dynamics.

# Define key species of ecological interest
spp <- c("Larvaceans", "Salps", "Jellyfish", "OmniCopepods", 
         "Euphausiids", "CarnCopepods", "Chaetognaths")

((zPlot_BiomassTimeSeries(out1, proportional = TRUE, species = spp) + ggtitle("Low Chlorophyll (0.01 mg m⁻³)")) /
    (zPlot_BiomassTimeSeries(out2, proportional = TRUE, species = spp) + ggtitle("Medium Chlorophyll (0.1 mg m⁻³)")) /
    (zPlot_BiomassTimeSeries(out3, proportional = TRUE, species = spp) + ggtitle("High Chlorophyll (4.0 mg m⁻³)")) /
    (zPlot_BiomassTimeSeries(out4, proportional = TRUE, species = spp) + ggtitle("Linear Increasing Chlorophyll")) /
    (zPlot_BiomassTimeSeries(out5, proportional = TRUE, species = spp) + ggtitle("Seasonal Chlorophyll Patterns"))) +
  plot_layout(guides = 'collect')

Results Summary

The comparison reveals how different chlorophyll scenarios drive distinct zooplankton community dynamics:

• Oligotrophic conditions (0.01 mg m⁻³): Limited productivity constrains overall biomass
• Mesotrophic conditions (0.1 mg m⁻³): Moderate productivity supports balanced community structure
  
• Eutrophic conditions (4.0 mg m⁻³): High productivity may favor certain functional groups
• Linear increase: Shows community response to gradually changing conditions
• Seasonal patterns: Captures natural temporal variability and community cycles

These results demonstrate the ZooMSS model’s ability to capture environmental forcing effects on marine zooplankton communities across different productivity regimes.